Go try some out and measure the ones you like. Most of the one piece ones around have that brace that you have to climb over and you bump your knees. Next time I would buy the kind with metal rails that allow you slide all the way across the seat and the plastic/fiberglass seats and tops are virtually maintenance free and easily cleaned so you have no paint, chipping paint, and food/grease/bbqsauce/bird droppings that soak into the wood and are a bear to clean. Sam's club carries these for $100 to $150 and compare that to the price of wood alone or a metal rail kit (at some home centers) with the wood, there isn't that much difference that would keep me from getting a durable plastic surface. They come with folding legs so you can fold them up and hang them up out of the way when they aren't in use like in the garage or on hooks installed on the wall by your patio. (I have brackets by the patio for hanging lawn chairs)
Some wood ones have the seat so close they are hard to get into. One that fits you may not fit the spouse and other folks. Think about a wood one with detached bench seats which can be moved around and used elsewhere. I bought some that have a seat and the back pivots from a chair back to a seat with a half top. You butt two of these together and have a full table with seats but you still have to climb into them but most of the time they are used as benches with chair backs on the patio. They are still wood though. I've seen these vinyl coated metal mesh tables but have also seen the vinyl come off and they rust.
If you make one, use screws and use bolts at all the critical pivot and brace points cause they do wear out and fall apart (parks are usually full of broken down tables that are being replaced). Also the boards warp and twist and someones sets a drink on a crack and spills it. Good luck.